Protective apparatus.



PATENTED JAN. 30, 1906 No. &10,914.

F. Bx GOOK. PROTECTIVB -APPARATUS.

APPLIOATION PILED DEG. 4, 1903.

2 SHEETS-SHBET 1.

PATENTBD JAN. 80, 1906.

B. BOOK. PROTECTIVE ABPARATUS.

APPLICATION FILED DEO. 4, 1903 2 SHEETS-SHEET 2.

wi nesses: ikan 2921:

%a mm@ sion electric dlsc switch oard, and alarm-circuits.

UNITED STATES PATENT OFFICE.

FRANK B. COK, oral-nemo, ILLINoIs.

IPROTECTIVE APPARATUS.

Specification of Letters Patent.

Patented Jan. 30, 1906.

Application filed December 4, 1903. Serial No. 183.733.

To (ll whom it may concern Be it known that I, FRANK B. Cook, a citizen o'f the United States, residing at Chicago,

in the'county of Cook and State ofIllinois, have invented new and useful Improvements in Protective Apparatus, of which the following isa full, clear, concise, and exactdescrip tion, reference being had to the accompany ing drawings, 'forming a part of' this specficaton.'

My invention relates to ap aratus-used in connection with protective evices for electric crcuits, and has for its object an' arrangement of such apparatus whereby the said protective devices may be readily and efficiently utilized. I

The arrangement of apparatus as shown in this invention is for supporting and Operating two classes of current-protective devices- -namely, protective devices which protect electric circuits and afaratus against high-tem rges, such as lig thing, and protective devices which protect against small fsneak-'currents" The high-tension electric discharges are guarded against by means of lightnng-arresters, preferably con-' sisting' of carbon blocks with interposed dielectrics, and`the sneak-currents are guarded against by means Dheat-coilsor thermal pro tectors.

This inventio comprises spring-supports provided with suitable Contacts and arranged for holding the lightning-arresters andheatcoils, the said s ring-supports'bein suitably mounted on a plate which is prefera ly a part of the iron su porting-frame and conductively connecte to earth. When this a pa ratus is used in connection with :telep one systems to provide protection therefor, the said. s ringsform terminals for the zlines,

paratus to -be tested;

` I will more particularly describe my inventjnby reference 'to the ac'companying drawings, l :55 ,Figure 1 isa-planview of theinvention.

ustrating same; in whic 2 is a side elevation of Fig. 1, showing When a form .of. heat coil and connectrg-sprngs shown in Fig.-5. Fig. 7 is a top end V ew of i Fig. 1. Fi' 8 is a sectional view of a modified form o the invention, taken the same 'as Fig. 3 ,`Wtl1 portions shown in elevation. Fig. 9 is a sectional view of another 'modified form of the invention, taken the same as Fig. 3, with portions shown in elevation; Fig. 10 is a top end view of Fig. 8. Fig. 11 is a top end view of Fig. 9, and-Figs. 12 and-13-are views of a modified form of support for s ringc of Fig. 1.

Like characters refer to lil: several figures.

The metal plate mis preferablya part of the iron framework supporting the strps of protective apparatus or a part of the iron framework of a distributing-board through which the telephone-Enes pass on theinwayt a central-station switchboard, and it is preferably connected to earth. It may be a art of any apparatus on which 'protective devices are mounted. The protectve devices and springs are mounted in pairs upon plate m and are preferably arranged so that 'the two devices orming a pair are mounted one on either side of this plate m and opiposite to each other. As the two protective evices forming a pair are similar to each other, I will describe' in detail only oneof the pair.

The conducting-strp r"is secured to one edge of plate m and is provided with' small rojectijons r r' thereon, between which proections carbon lightning-arresters a a are placed. This ound-'strp r forms the sub- ;ect-matter o my co ending application, Serial No. 219,645, file August 5, 1904, for ground-strips for protective apparatus, which s a division .of this present application. Springs'e', f, d,'c, and bare all-mounted flatwise on one side of plate mby-two double ended bolts s and t, -as shown in Figs! 1, 2, and 3. The bolts s and t pass through suitable holes in plate m, but are in'sulated from m by suitable insulating-sleeves and washers u, preferably of hard rubber. Spring e' is mounted next to plate m, but insulated therefrom, and is provided with &contact at its three sets of the protective apparatus mount-` e parts in the free end adaptedto Inale contact with the ground strip 'rwhen springfe is depressed and' With 'whole there'irithroughwhich an in Vided with a narrow portion which extends astthe forwarded e. of late m, so asto htnin -ar rester e,`

The carbon bloeks of the lightning-arrester, With an interposed dielectric are inserted 'also provided 'with 'a' hole therein through whichacontact point passes when the heatsulating-pin l passes andrests against' the plate m. This s ringeisfiused for closing-an alarm circuit. princg f is mounted next to spring e, but insu ate therefrom, and is proorn'i e support fo`r' t 'e lig between sprinf and 'ground-strip and are held in place y' the tension in spring f and the projee'tions' 1' r on strip r Spring f is coiloperates andf'vith 'another hole therein through which the isulating pin ,p Z passesf The insulating'pn z is' proiided with a shulder near its iij'nr end, against which spring e,

restsj said shulderbeing adapted to hold spring "e oirt' of* dism'ount'dj against springfi 'so as to make electricaleiitict thefwith; is frmed into a' thimble geg-i s f eendedgpted to receive and-hold the bodyg qf the beat-coil, and is provided witha contct?point Ic, adapted to pass through aholeiiifspringf and make 'cenewhen the heat coil operates, e the'rin 'through which the 'frelj `Sprin c is d, but 'insu ated I the'rf'rom, is j rovided with a lip at its free which' rest si't spring c and make con tacttherewit spring b being split at b so as to ive two independent points of contact b is adapted and iutended to or'm a switc -socket with spring c, in which' socketa test-plug inay .be inserted to breakthe contact between springs b and c and allow the different circuits through the' protecti ve apparatustobe' tested, the coni tact p'oints'on spring b serving top'revnt lateralflisplaenient of the test-plum The test-plug adapted to "be used with t 's protectie apparatus' forms the subject-matter of my co ending application, Serial No. 202,653, ed' Aprilll, 1904,- for test-plug for fi otectife aPParatus, which i's a division of t s present application. heatcoillandsprings in atset position, while the r ght-hand sdeof these figures shows the heat-col and sprngs in an operated position; Qn' the right-handsde of Fig .`3 spring b is in'- contact with' sprng'f. Spring 2 4 vember 14, 1903, for heat-coil.

Thle ftlanfdside of Figs. 1 and 3 shows the be readiiy seen thetterminal b is conductively i connected to spring b on the opposite side of 'plate m from`b' through the agency of bolt'* and that terminal f is conduetivelyconnected to springs d and fon the opposite side. of plate m from f 2 through the agency of bolt s. This arrangement puts the line-terminals f* and f on one side of the plate m' and, the switchboard-terminals b ,and I on the other side of plate m, as' shown at the lower part of Fig. 3. The alarm-annunciators p p 'are connected eto the alarm-sprin se e, respectively and to azconinon source o electrieity n; T he source n' is also connected. to thefgroundplate m,a`s'shoWninFig.1 3

The beat-coil which I preferablyuse in this invention is shown ,in section iiiFig. 4 `but I desire it to be understood that other forms of heat-coils may be equally used. The heatcoil herein shown consists of ahollow ht-i conducting element e apin 7', Secured therei by fu'sible material j a tootled wheel-% secured to thepn j; a coil %2 wound upon the core 6 .insulating-washers 'uplacedone on' either end of the Corea and a Conducting casing g supported by thewashers u? u and inclosing the coil e The terninals of coil e are connect-ed to the core e and the czsllg g respcctively. shown, described, and claimed in my copeiding application, Serial Nof181, 211, filed No- When an abnornally `large .current trav- This leat coil of Figje is erses the w'i'idiig e of the heatcoil for a short length of time, it heats the coree? thereof, which conduets the heatto the fusible na When the heat is suflicient, the fusiterial j ble material softens, thus allowin the pini to turn within the hollow core e j %Vilen the heat-coil is placed in a set iositionin relation with the s rin s d and 'c o the rotective a paratus, t body of the 'coil s held'withn the hollow end of spring dand :a tooth of the toothed' wheel -i is engaged by tle lip (n-the' This ei1` agemeht offree end of spring. spring c with the toothed whee ikeeps'the contact-point k 'out of contact with spring?,-` as shown on the left-hand side ofsFigs'. land 3. When the'pin ;i is free 'to 'turn withinthe hol-` low core e ,-due to the sible'iiatei'ial 'j softening, thetoothed wheeli turns with the pin j, due 'to the'tension in'spring d,` aid thereby.

releases itself from thespring. i 'Thisa'llows the contact-point kof ring" d-tofcome-in contact with spring e an cause the letter to 1 make contact with the ground-plate m, as'

&10,914 3 shown. on the right-hand side of Figs. 1 and 3. It will be seen with this position of the *s rings that the line-spring f is grounded t ou h the agency of springs e and d, also that the alarr'n-circuit is closed through the in the hollow core e', and the heat-coil is ready to ber'eset.

The lightning-arrester a operates in a man- 'ner well understood. When a high-potential charge ;comes in over the line-spring f, it discharges from one carbon block to the other through the thin interposed 'dielectrc and passes through the strip r and ground-plate m to earth, as at o in Fig. 1. In Figs. 5 and 6 I have shown a modified form of heat-coil and engagenient spring. Instead of the heat-coil beng sup lied` with a toothed wheel 'i it is su plied wt a contact piece or cam g', ada ted to engag spring cin a slot c in one en -thereof, spring e' being provided with a tongue c adapted to restore the heat-coil to operative siton after operation. When the heat-co operates, the contact-piece g' takes the. position g and the heat-coil 'takes the relative osition with respect to spring indicated by the -dotted- Wen the heat-coil is reset, the tongue enga the cam g* in the position g and *turns the atter back to its original posi- I tion, where it again engages the springc', as

Originally; the heat-coil at the same time turning in the thimble g; 'Any conducting member, such a's a wire, may be used for `g*. In F` *8 and 1 0 I have shown a modified form o "the protective apparatus. The

ground-plate m, l' htning-arresters a a, stri r, springs e e and b bolts s and t, and ternnals b' and f* being the sameas inFi 1. In this nodified form spring f' takes'teplace of 'sprngf of Fig. 1,' the hole in a, through which an insulatng-pin Z' passes, closer to the lightning-arrester than in ig. 1.' Spring d' is mounted next to spring f* and conductively connected therewith. It is provided with a lip at its free end, in which is cut a hole h', adapted to e age the toothed wheel 1 of the heat-coil wi a hole through whch the insuIating-pin I' passes and with a hole through which a contact-piece asses.

The pin l' su ports spring d'. in a rigi position and hol s spring e out of contact with spr ng f' .Srng c' is mounted b'etwen sprngs d'and but insulated therefrom, and

s. provided with a--portion c', adapted to ma econtact with spring d' when the heatcol operates. Spring k' s secured to sprin e', sprovided `wth a. contactiece adap to pass'through springs d' an f and press 'spring e against gr'oundlate 'm when the heat-coil operates 'ble at one end for holdingthe heat-coil thereand is ormed into a thim- -support for spring c.

a st-ess .through springs d and f makes contact with the plate 1 direct, when the heat-coil operates, and thereby grounds all of the springs of the group, as shown on the right-hand side of Fig. 9.

'Figs 12 and 13 show a modified form of The 'su port consists of a thick rigid piece c formed to lie against spring c, as shown, and takes the place of the insulatin -suppo-t l of Fi 1'.

While' have described particular details of construction in this invntion, I do not wish to limit myself .to such exact details.

The general arrangement of such apparatus'- is what I desire to hereinafter claim.

Having thus described my invention,what I claim as new, and desire to secure by Letters Patnt,'is v 1. In protective a paratus; the combinetion with a ground-p ate,` f a pair of superosed springs mounted flatwse thereon but nsulated therefroni and from each other, one spring of the pair being rigidly supported by a suitable su port, a `protective devce adapted to be held in a state of Stress b the said springs and conductively connecte from one spring to the other, a third spring outside of the IOO said pair and mounted flatwise on the groundplate, but insulated therfrom .and from the pair of sprngs, at its Inountin the said third spring making contact with?) e outer spring of the pair at its free end, the said third spring -and inn`er s ring 'of the pair being switchboard and ine terminalsj f'espectively and means for grounding one spring of the pair -when the protective' device operates, substanmsulated therefrom and from each other, one

sprn of the pair being held stationary' bg a suita le support, one of the said sprin eingformed into a thimble at its free en the other said spring being provided with a lip at its free end, a heat-col adapted tobe firmly held. in the said thimble, a conduc ber`on the heat-coil, adapted to engage 'the saidli the heat-coil being held in a state of hy the saidsp'ings, a third s 'ring outside of the said ;air and mounted the ground-plate, h't insulated therefronr and from the pair of sprin'gs, at itsmounting, the' said third spring making contact with the outer spring o the pair at its free end. the

said third.s ring and inner spring of the pair being swite board and line terminals, respectiveiy and means for ground-ng one spring of the pair when the heatcoil operates, substan- --taliy as described.

, 3. :In protective'a paratus',' "the combinatorwith aground-p ate, of bolts extending ther'ethrough and insulated therefroni and fromeac'h other apar of su'p'er'posed springs state of Stress bythe sai mounted flatwise on the said plate by the saidbolts and insilated rom .the said plate, and from eaehbther, one spring of the p'air being rigidly supported by a suitable support, a proteetive deviee ada ted to be held in a springs andconductively connected fron one spring to the other, a thrd spring outside of the 'said pair and mounted 'flatwise on the oind-plate bythe said bolts., the said thir spring being insulated from the grouiid-ilateand from the pair of'springs, at its inountin and making contact with* the outer sprin'ohthe pair at its 4 t e.

free end, .the third sprin an einner spring 'of the pahbei switch oardandjline termi- 2 5 nals, respective andmeansfor grounding one sprng of the pair when the roteetive desta ;tion a ground-p posed--springs vieeo atefsu ntially as eserb-d.

(4; ,protective apparatus; the combnaate ,of a pair of supermounted nsulated ;therefrom and'romeachother; one

sprir of the pair being rigidly suppirted by a.

. suita le"s pport,- aproteetvedeveeadapted to be held ma state -of Stress by the 'said springs and conductively connectedfromone I spring to the other, a third spring outside of t e'.` said air and mounted flatwise on' the roun -p ate,' but 'insuIated-.therefrom and "s, at'its mountin the rom'the air 'of sprin said thir 'spring maiiing'cont aet wt the outer spring-of the pair at its free end, the

` saidthird s ring and inner spring of the pair being switc board and line terninais, res ectively theouter spring of-the pair being ead at its mounting, and means for' groundng the movable 'spring of the pair by the o eration.

of the dproteetive device, substantial y as deseribe 5. In protective apparatus, the eonbina- 'tion with a ground-plate, of bolts extending therethroigh and insilated therefron and from each other, a pair of superposed springs -mounted flatwiseaon the said plate bythe'said bolts, and insulated froni the said phte and from each; other the: outer s ring 'of the pair being insulated ironi the sai bolts, the-inner spring of the pair being oonductively Secured to one-of the said bolts and insuhted from the other, one of the said springs being rigi ly supported' by asuitable support, aprotectve devce adapted tobe connected between the pair of* sprmgs at their free ends, the said de-' vice being held in a s'ta-te of Stress bythe tension in the said springs, a third spring outside of the said pair and mounted flatwi'se on the fiatwise the eon and gropnd-p iate by the said bolts, the 'nird sprng being nsuiated 'fromthegronnd-phte,

from the pairofsprngs and ironi the said bolts, at its mountng, and adapted to make contact with the out-er spring of the pair at its free end, the third spring and the inner spring of the pair being. switehbozrd and line terininais, respoetiveiy, and means operitcd by the giving away of the protcetive device, Whereby the iinierspri'g oi" the pair is ground, substant aily as' described.

6. In protectve apparatus, -theeombnation with a ground-p1at0,of a pair oi" 'superpair of springs and for'ni'ng a' ifit of the' n'u'v'- able spring of the said pair; t ieiorth spring being adapte'd tobe eltrieanj onnected with the rgid spri'ig' of thepair-wlin the proteetve devce-operates;`-and a proj'etion fron 'the movable spring of the pai' adapte d to make -eonnection with-the 'gronndfplate when.

the protective devie 'operatefnd thereby round nu of the springs of -'the en'bination, substantially as described. T

7. In proteetivea "parat isf the conbina tion with a ground-p te of a pair ofsuporosed springs mounted fiativise'tiiereon and nsuiated therefrom-'andfi'orrf efter other, one

of the said springsibeing rigidiy"supportcd the othersaid 'spring being free to move, a' protective deviee held in a state=of stressfbctween the said springs'and*eondutively connected froni one spriig'fo'f the air to the -other, a third s ringfoutside-f t ie'said pair and mounted' atwis'e' on 'the gro'iind-plal e but insulated from the "gronid plate and froni the air of springs at' its'ifi' vend; the said thir( spring' naking contdt vithl the 'enter spring of the pair at fourth spring ite'psd'bbt 'e'nihe phifldi' spriigs and forning. afp'artmfthe n' i spring of the pair, `a*fi th spriig .between the gronnd-piai'warfi ground phit e fansi.. ins'uhi't d' froni the ha t ter and from the -other'sprixigs'oi'tlie t', ti i id fourih'spring being adaptod to r E connected with `the" ri 'd `p'fi''gj of the pair -when the protective' r e'vi'c-. joperats; anii -proje'i-.tion on the novablesprng Milto pnzi adapted to make electrivii connection w th the ground-piate when the proteetive denu &10,914

operatesfi and: therebyfground all of the s rings of the combination, substantially as escribed.

S. In protective apparatus, the combination with a ground-plate, of a pair of superposed. springs mounted flatwise thereon but insulated therefrom and from each other, one spring of the pair being held stationary, the other s ring being free to move, and one of the sai spr n s being formed into a thimble at its free en, the other said spring being provided with 'a lip thereon at its free end, a

eat-coi] adapted to be inserted in, and firmly held by, the said thmble, the said heat-coil being provided with a hollow core and a in secured therein by fusible material, and a eonductng member Secured t'o the said pin and adapted to engage. the said lip, an abnorbeing mally large current traversin the winding of the heat-coil for a suflicent ength of time, causing the fu'sible material thereof to soften and thus 'allow the said pin and conducting member Secured thereto, to turn, thereby rel'easing the said conducting member from the said li and grounding the movable spring of the pair, substantially as described.

9. In protective a paratus, the combination with a .ground-p ate, of a pair of su erosed springs mounted flatwise thereon ut insulated therefrom and from each other, one s ring of the said pair being held stationary, t 'e other spring being free to move, and one of the said sprin s being formed into a thimble at its free en the other said spring being provided with a lip thereon at its free end, a heat-coil adapted to be inserted in, and firmly held by, the said thimble, the said heat-col Cprovided with a hollow core and a pin secure therein by fusible material, a conductingmember secured to the said pin and adapted to. engage the said li an abnormal y large current traversing t e winding of the heat-coil for a suflicient length of time, causing the fusible material thereof to soften and thus allow the said pin and conducting member secured theret'o, to turn, thereby re- -leasing the said conducting member from the said lip and'rounding the movable spring of. the pair, an means adapted to en age the said conducting member and there y tum the heat-coil within the said thimble, when the protectiveapparatus is reset, the said lip again engaging the said conducting member as origina1ly,- substantially as described.

10. In protective a paratus, the combination with a groundp ate, of a ground-strip' secured to one edge thereof a spring mounted flatwiseon the ground-piate' and msulated therefrom, a second sprin between the firstmenticned spring and t e ground-plate, mountedflatwseon the groundlate and insulated 'therefrom and from thetst nentioned sprin apair of supe osed springs outside of t e rst-mentione spring. and mounted fiatwse on the ground-p late but insprin sulated therefrom and from nd. Lh 'the inner pring of the said pair being onductively .s -u red to the first-mentioned spring, one spring of the pair being held stationary,

the other spring of the pair being movable, a 7 o fifth spring outside of the said pair of springs, mounted fiatwise on the ground-plate and insulated from the ground-plate and from the other said springs, at its fixed end, and making contact with the outer spring of the pair at its free end, a lightning-arrester inserted between' the free end of the first-mentioned spring and the ground-strip, and a protective device held in a state of stress between the said pair of springs, the giving away of the protective device, due to an abnormally large current therein, causing the movable spring of the pair to ground itself and the secondmentioned spring, substantially as described.

11. In protective apparatus, the combination with a ground-plate, of a ground-strip Secured to one edge thereof, a spring mounted flatwise on the ground-plate and insulated therefrom, a second spring interpsod between the first-mentioned spring and the o ground-plate,mounted flatwise on the groundplate and insulated therefrom and from the first-mentioned spring, a'pair of superposed springs outside of the first-mentioned spring and mounted fiatwise on the groun'd-plate but insulated therefrom and from each other, the inner spring of the said pair being con- .ductively Secured to the first-mentioned spring, one spring of the pair being provided with a projection thereonadapted to make roo contactwi'th the other spring of the pair, and another projection thereon adapted to make contact with the second-mentioned spring, which is adapted to make contact with the ground-plate, one spring of the pair being o5 held stationary, the other spring of the pair being movable, a fifth sprin outside of the said pair of springs, mounte flatwise on the ound-p1ate and insulated therefrom and om the othersaid springs, at its fixed end, ro

and making contact with the outer spring of the pair. at its free end, the said fifth 'spring being split at its free end to form two points of contact, a lightning-arrester inserted be tween the free end of the first-mentioned 1:5 i

s ring and the groun'd-strip, and a protective evice. held in a state of stress between the said pair of springs, the giving away of the protective device, due to an abnormally large current therein, causing the movable spring zo of the' pair to throw a ground on all of the of the combination, substantially as described.

2. In protective apparatusfthe combinetion with a ground-plate, of a ground-strip Secured to one edge thereof and spitably ar- *ranged to accommodate lightning--arresters,

a spring mounted fiatwise 'on the groundplate and insulated thererom, a pair of superposed springs outside of the first-men- 3 v iourth spring tioned spring and mounteci fiatwise on the 'round-nlate but insulated thereirom and ?roni each other, the inner spring of the pair being conductiveiy Secured to the first-mentioned spring, one spring of the pair being held statonary, the other spring oi' the pair being movable, a projection on one spring of the pair adapted to make connection between the two springs of the pair, a projection on one spring of the pair adapted to make electricai connection With thegroundpiate, a outside of the said pair of springs, mounted iatwise on the groundpiatc and insuiated therei'rom and from the other springs at its fixed end, and making contact-With the outer spring of the pair at itsfree end, the said fourth spring being split atits free end o form twe points of contact, a lightning-arrester inserted between the free end of the first-mentioned spring and the ground-strip, and a protective device held in a state of stress between the said pair of springs, the giving away of the protective cievice, due to an abnormaliy large current theren, causing the movabie spring of the pair to ground all of the springs oi the cembination, substantiaiiy as described.

13.. in protective apparatus, the combinetion With a ground-piate, of douhie-ended bolts cxtending therethrough and insuiated therefrom and froni -each other, groundstrips seeured toone edge of the ground-piate and held against each other, a pair of superposed springs on each side of the ground-` piate and' moun'ted fiatwise on the groundpiate by the said bolts, the said springs being insuiated from the ground-piate and from each ot her, cne spring of each pair being held stationary, the other spring of each pair being movabie, a protective device for each pair oi springs and held 'in state of stress therehy, a third spring for each pair, mountcd ile twise on the ground-piate between the latter and the respective pairs oi springs, bythe said bolts, the said third spring-s being conductively` Secured to the respective' inner springs of the pairs, iigitning-arresters inserted between the respective third springs and the ground strips, a i'ourth spring ior each pair mounted iiatwise on the ground-piate by the said bolts, outside oi' the respective pairs of springs, the .said i'ourth springs nmiiing contact with the respective outcr spring-s oi' the pai's ili their i'i'ce cnds, and being insuiacd from the said pzil's at their iixed ends, ami a terminal springior each side oi the groundpiatc and nmnnteii thereon by the said bolts, but insuiated i'rom the ground-piate and from each other, one oi' the said terminal springs and the opposite said third spring' .being conductiveiy sceurcd to one said boit, the other said terminal spring and its hpcsiic said i'ourth spring being conductiv'jiy sccnrcd te the other said bolt, this "changing ever oi' the springs being done to put the co'mection- &0,914

terminais for bot'h said third springs side of the ground-plate, and the COlilCa'iiOllterminals for both said fourth springs on the other sidefiof the ground-piate, the giving away of the protective devices, due to abnormaily large currents therein, causing the movable springs of the respective pairs to s prngs, substantiaiiy as described.

14. In apparatus of the class specified, the combination of a thimbie an. excess-current-operabie device contained within the thimbie, means for cngagng a portion of the said device and tending to turn same within the thimble, and means for turning the said device within the thmbie, to an operative position, after operation. i

'15. in apparatus of the class specified, the combination of a device opera ble upon an' excess of current and comprising a conducting member normally Secured in place by heat-susceptibie material, a thimble in the nature of a spring adapted to grasp the said device and firmly hold' same theren, means for engaging the said conducting member and tending to turn the said device within the thimbie, the said conductin member releasing its engaging means When the heat-susceptibie material is soi'tened, and means-for turning the said device within the thi'mbie to reset the apparatus.

.16. in apparatus oi the class specified, the combination of a spring mei iber iormed into a thimbie at one end thereoi', a thermal protecto' contained within the thimble and i iirmiy held against rotation by the iatter, a

i conducting member eiectricaiiy connected i with the proteetor and held in an operative position by heat-susceptibie material, a second spring member adapted to engage the said conducting member and tundim;` to turn 4 the said device within the thimbie, the said second spring' member being released by the said conducting .member when the protector operates,vand thereby controiiing a circuit,

i and means adapted to engugc the said coni ducting member and tiereby turn the protector within the ihimbie,toan operative position, when the apparatns is reset, substantialiy as described.

I 17. In proteetive apparatus ior eiectric circuits, the combination with ground- I piate, oi a gronnd-strip secured thereto, a sei ries oi' iirhtning-arrestcrs held against the i ground-st'ip, a series oi' spring-supports g adapted to hold the respective lightning-ar- I reste's in place, a second .series oi" springs conductiveiy connected with the respective i springs oi" the iirst series, a'tiird series of spi'igs i'orming pairs with the respective springs of 'the second series, a series of ther- I i i mai p 'ctec tors held in a state of stress between .the respective pairs of springs, a

I fourth series oi' springs adapted to normally 1 cngagc the respective springs oi* one scries ene ground themselves' and their respective third' IOO . ol' the deviee under abnormal conditions, to

&310,914 '7 (leviee operable upon an excess ol' current in the circuit, means for holding same in an operative position, means for Operating the (levice under abnormal conditions, and means for turning the device :s a whole to an opera- 'tive position after operation.

forming the pziirs and means for grou'nding one spring of any pair upon the operation ol' 'its prot.-:tor.

18. ln appzrztus of the class specified, an electric protectivo device, a thimble :dzpted to ;'rnsp the said (levice and nornnlly hold sne in a fixed position, means 21. In oppartus of the class specified, a :dnpted to ongzge the device and tending to device opereble upon an excess'of current in operate szune, the operation of the device l the circuit, means for holding same in &n opczusinr u rircuit to be controll( l., and means i erutive position, means for turning the cen- :uhpted to more the szil device within the trnl portion thereof under abnormal condi- Ihinlleto operative position after operation. l tions, to control :L circuit, and means for lt). l ppzrztus ol the class specified, zl turning the device as a whole to an operative dovice operable upon ::n excess of current in position after operation. the cireuinmezns for holding same in nn op- In Witness Whereof I hereunto subscribe my M'zltve position, means for turning a portion name this 2d day of December, A. D. 1903.

FRANK B. cooK.

control a circuit and means for turnng the deviee as u whole to an operative position after operation.

20. In apparatus of the class specified, a

VV'tne s ses:

J NO. F. ToMKINs, FRED. R. PARKER. 

